As a kid, this question always amused me, if learning karate will protect you from bad guys, what’s to stop bad guys from learning it? Or what’s to stop me from being a bad guy?
Guns, same thing. So, while it’s great to constantly learn new techniques, there’s no end to bad people learning good tools. Tools are just that, for you to use in situations of need, or want 😛
As a knife or gun defense develops, the next step is for the other side to respond. Sadly, this is old news, guns are always better than human strength.
If self defense worked so well, why do Krav Maga instructors own guns?